9. Phase III Clinical Trials - Development for Launch
Step 9. Phase III Clinical Trials - Development for Launch
Phase III trials (also called confirmatory studies)
are the largest, most complicated and most expensive part of the development of
a medicine. They aim to confirm the efficacy and safety in a large patient population.
The decision to go on to Phase
III trials is only made if it is supported by all the information from earlier
studies, manufacturing, and business units. The design of such trials is also
critically important. Therefore, there is a large amount of discussion with
external experts, Regulatory Authorities, patient groups and others. This ensures
that the right questions are being asked and the right information is being
collected. The number
of patients in the trial is also very important so that the results
can be properly interpreted and will meet the requirements of sound scientific
rigour.
All of the information
gathered from the earlier stages is used to make important decisions including:
- The final formulation of the medicine (how the active medicine is combined with other chemical substances).
- The dose to be tested.
- Which patients can be recruited (inclusion criteria).
- Which patients cannot be included (exclusion criteria).
- How many patients are required (sample size).
- The trial design.
- The length of the trial.
- How efficacy and safety will be measured.
- The statistical tests that will be used.
At this stage, the trials may
involve thousands of patients, are often run in many countries, and require extensive
expertise to run them effectively. They are therefore time consuming and
cost-intensive. However, this is the only way to allow a clear benefit-risk
assessment between the efficacy of the medicine (it works) and its safety (it
is well tolerated).
Summary: Phase III studies make up the largest, most
complicated and most expensive part of the medicine development process. Over
50% of the medicines fail in this step. The overall failure rate for the
projects from the discovery stage is more than 97%. The revenue from the few medicines
that make it to the market, will cover the cost of all the projects, the
failures as well as the successes.